补喂赖氨酸和苏氨酸对放牧条件下泌乳母马血液生化指标的影响OACSTPCD

This experiment was to study the effects of supplementing lysine and threonine on blood biochemical indexes of lactating mares under grazing conditions so as to provide reference for amino acid regulation for the health of lactating mares.In this study,24 Yili mares with similar foaling date(May),8-10 years of age,parities of 3-4 parities,average weight of(428.00±33.42)kg and lactation for 30 days were selected.The mares were randomly divided into 4 groups with 6 mares in each group,which were the control group,trial group Ⅰ,trial group Ⅱ and trial group Ⅲ,respectively.Under the same grazing conditions(the same grazing time,drinking time,milking time and graz-ing pasture).The control group was not fed with any amino acid supplement.Each horse in trial group Ⅰ was fed with a diet supplemented with lysine 40 g/d+threonine 20 g/d,the diet for each horse in trial group Ⅱ was supplemented with lysine 60 g/d+threonine 40 g/d,and that of each horse in trial group Ⅲ was supplemented with lysine 80 g/d+threonine 60 g/d.The supplementary feeding experiment lasted for 120 days,and then the cervical vein blood samples of the mares were collected regularly to determine the relevant biochemical indexes.The results were as follows:In terms of protein metabolism,the contents of total protein and albumin in the blood of the mares in trial groups Ⅰ,Ⅱ and Ⅲ were significantly lower than those in the control group(P＜0.05),and the uric acid content was increased by 16.33%,37.20% and 17.58%,respectively.In terms of glucose and lipid metabolism,the total bilirubin of trial groups Ⅰ,Ⅱ and Ⅲ was significantly higher than that of the control group(P＜0.01),their glucose and triglyceride contents were lower than those of the control group.In terms of en-zyme activity,the activities of alanine aminotransferase and aspartate aminotransferase in trial groups Ⅰ,Ⅱ and Ⅲ were significantly lower than those in the control group(P＜0.01).The activity of alkaline phosphatase and creatine kinase increased with higher doses of lysine and threonine.In terms of mineral ions,there were no significant differences in the contents of Ca2+,inorganic phosphorus and Mg2+among all the groups(P＞0.05),but the contents of Fe2+in trial group Ⅱ were the highest,and there were significant or extremely significant differences when compared with the other three groups.In conclusion,supplementation of lysine and threonine to the diet for lactating mares under the same grazing conditions reduced the activities of glucose,triglyceride,glutamic oxalacetic transaminase and glutamyl transaminase in their blood,increased the contents of total bilirubin,inorganic phosphorus,Mg2+and Fe2+,and promoted the health of the mares.The intake of 60 g/d of lysine and 40 g/d of threonine for individual lactating mare was the most effective.